▎ 摘　　要

NOVELTY - Positive electrode (301) comprises a positive electrode active material layer (201) over a current collector (101). The positive electrode active material layer comprises many particles of a positive electrode active material (102), a graphene oxide, and a polymer having a functional group as a side chain, where the polymer is bonded to the graphene oxide, and at least a part of the graphene oxide is in contact with at least one of the particles of the positive electrode active material. USE - The positive electrode is useful in a secondary battery (claimed), which is useful for power supplies of a variety of electric appliances and electronic devices which can operate by electric power including display devices of TV and monitors, lighting devices, desktop personal computers and laptop personal computers, word processors, image reproduction devices (which reproduce still images and moving images stored in recording media such as DVDs and portable compact disc players), portable radios, tape recorders, headphone stereos, stereos, table clocks, wall clocks, cordless phone handsets, transceivers, portable wireless devices, cellular phones, car phones, portable game machines, calculators, portable information terminals, electronic notebooks, electronic-book readers, electronic translators, audio input devices, video cameras, digital still cameras, electric shavers, high-frequency heating appliances such as microwave ovens, electric rice cookers, electric washing machines, electric vacuum cleaners, water heaters, electric fans, hair dryers, air-conditioning systems such as air conditioners, humidifiers and dehumidifiers, dishwashers, dish dryers, clothes dryers, futon dryers, electric refrigerators, electric freezers, electric refrigerator- freezers, freezers for preserving DNA, flashlights, tools such as chain saws, smoke detectors, medical equipment such as dialyzers, and industrial equipment such as guide lights, traffic lights, belt conveyors, elevators, escalators, industrial robots, power storage systems and power storage devices. ADVANTAGE - The positive electrode: has increased proportion of the positive electrode active material in a positive electrode active material layer; exhibits increased strength; and provides secondary battery with increased capacity per unit volume, and increased safety. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a secondary battery comprising the positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; and (2) manufacturing the positive electrode, comprising: mixing the particles of positive electrode active material, graphene oxide and water; adding a polymer aqueous solution to the mixture (103) of the particles of the positive electrode active material, the graphene oxide and the water to form a slurry; applying the slurry to the current collector; drying the slurry to form the positive electrode active material layer; and reducing the graphene oxide in the positive electrode active material layer. DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of the positive electrode. Current collector (101) Positive electrode active material (102) Reaction mixture (103) Positive electrode active material layer (201) Positive electrode (301)